Adds system graceful stop tracking events

3 new events are added, they are:

* STOPPING_SERVICE - published before service is stopped
* SERVICE_ITEM_STOPPED - published each time service item(like workspace) is stopped
* SERVICE_STOPPED - published after service is stopped

wsmaster/che-core-api-system-shared/pom.xml

@@ -38,6 +38,10 @@
             <groupId>org.eclipse.che.core</groupId>
             <artifactId>che-core-api-dto</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.eclipse.che.core</groupId>
+            <artifactId>che-core-commons-annotations</artifactId>
+        </dependency>
     </dependencies>
     <build>
         <resources>

wsmaster/che-core-api-system-shared/src/main/java/org/eclipse/che/api/system/shared/dto/SystemServiceEventDto.java

@@ -0,0 +1,31 @@
+/*******************************************************************************
+ * Copyright (c) 2012-2017 Codenvy, S.A.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Codenvy, S.A. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.che.api.system.shared.dto;
+
+import org.eclipse.che.dto.shared.DTO;
+
+/**
+ * DTO for system service events.
+ *
+ * @author Yevhenii Voevodin
+ */
+@DTO
+public interface SystemServiceEventDto extends SystemEventDto {
+
+    /**
+     * Returns the name of the service described by this event.
+     */
+    String getService();
+
+    void setService(String service);
+
+    SystemServiceEventDto withService(String service);
+}

wsmaster/che-core-api-system-shared/src/main/java/org/eclipse/che/api/system/shared/dto/SystemServiceItemStoppedEventDto.java

@@ -0,0 +1,56 @@
+/*******************************************************************************
+ * Copyright (c) 2012-2017 Codenvy, S.A.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Codenvy, S.A. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.che.api.system.shared.dto;
+
+import org.eclipse.che.api.system.shared.event.EventType;
+import org.eclipse.che.commons.annotation.Nullable;
+import org.eclipse.che.dto.shared.DTO;
+
+/**
+ * See {@link EventType#SERVICE_ITEM_STOPPED} for details.
+ *
+ * @author Yevhenii Voevodin
+ */
+@DTO
+public interface SystemServiceItemStoppedEventDto extends SystemServiceEventDto {
+
+    /**
+     * Returns an item for which this event is published(like workspace id).
+     */
+    String getItem();
+
+    void setItem(String item);
+
+    SystemServiceItemStoppedEventDto withItem(String item);
+
+    /**
+     * Returns an amount of items currently stopped, it's either present
+     * with {@link #getTotal()} or missing at all(null is returned).
+     */
+    @Nullable
+    Integer getCurrent();
+
+    void setCurrent(Integer current);
+
+    SystemServiceItemStoppedEventDto withCurrent(Integer current);
+
+    /**
+     * Returns total count of items which had not been stopped before
+     * service shutdown was called. It's either present with {@link #getCurrent()}
+     * or missing at all(null is returned).
+     */
+    @Nullable
+    Integer getTotal();
+
+    void setTotal(Integer total);
+
+    SystemServiceItemStoppedEventDto withTotal(Integer total);
+}

wsmaster/che-core-api-system-shared/src/main/java/org/eclipse/che/api/system/shared/event/EventType.java

@@ -20,5 +20,28 @@ public enum EventType {
     /**
      * Published when system status is changed.
      */
-    STATUS_CHANGED
+    STATUS_CHANGED,
+
+    /**
+     * Published when system is starting shutting down a service.
+     * This is the first event published for a certain service.
+     *
+     * <pre>
+     *     STOPPING_SERVICE -> (0..N)SERVICE_ITEM_STOPPED -> SERVICE_STOPPED
+     * </pre>
+     */
+    STOPPING_SERVICE,
+
+    /**
+     * Published after service item is stopped.
+     * Events of such type are published between {@link #STOPPING_SERVICE}
+     * and {@link #SERVICE_STOPPED} events.
+     */
+    SERVICE_ITEM_STOPPED,
+
+    /**
+     * Published when shutting down of a service is finished.
+     * The last event in the chain for a certain service.
+     */
+    SERVICE_STOPPED
 }

wsmaster/che-core-api-system-shared/src/main/java/org/eclipse/che/api/system/shared/event/service/StoppingSystemServiceEvent.java

@@ -0,0 +1,30 @@
+/*******************************************************************************
+ * Copyright (c) 2012-2017 Codenvy, S.A.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Codenvy, S.A. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.che.api.system.shared.event.service;
+
+import org.eclipse.che.api.system.shared.event.EventType;
+
+/**
+ * See {@link EventType#STOPPING_SERVICE} description.
+ *
+ * @author Yevhenii Voevodin
+ */
+public class StoppingSystemServiceEvent extends SystemServiceEvent {
+
+    public StoppingSystemServiceEvent(String serviceName) {
+        super(serviceName);
+    }
+
+    @Override
+    public EventType getType() {
+        return EventType.STOPPING_SERVICE;
+    }
+}

wsmaster/che-core-api-system-shared/src/main/java/org/eclipse/che/api/system/shared/event/service/SystemServiceEvent.java

@@ -0,0 +1,59 @@
+/*******************************************************************************
+ * Copyright (c) 2012-2017 Codenvy, S.A.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Codenvy, S.A. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.che.api.system.shared.event.service;
+
+import org.eclipse.che.api.system.shared.event.SystemEvent;
+
+import java.util.Objects;
+
+/**
+ * The base class for system service events.
+ *
+ * @author Yevhenii Voevodin
+ */
+public abstract class SystemServiceEvent implements SystemEvent {
+
+    protected final String serviceName;
+
+    protected SystemServiceEvent(String serviceName) {
+        this.serviceName = Objects.requireNonNull(serviceName, "Service name required");
+    }
+
+    public String getServiceName() {
+        return serviceName;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof SystemServiceEvent)) {
+            return false;
+        }
+        final SystemServiceEvent that = (SystemServiceEvent)obj;
+        return Objects.equals(getType(), that.getType())
+               && Objects.equals(serviceName, that.serviceName);
+    }
+
+    @Override
+    public int hashCode() {
+        int hash = 17;
+        hash = 31 * hash + Objects.hashCode(getType());
+        hash = 31 * hash + Objects.hashCode(serviceName);
+        return hash;
+    }
+
+    @Override
+    public String toString() {
+        return getClass().getSimpleName() + "{eventType='" + getType() + "', serviceName=" + serviceName + "'}";
+    }
+}

wsmaster/che-core-api-system-shared/src/main/java/org/eclipse/che/api/system/shared/event/service/SystemServiceItemStoppedEvent.java

@@ -0,0 +1,98 @@
+/*******************************************************************************
+ * Copyright (c) 2012-2017 Codenvy, S.A.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Codenvy, S.A. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.che.api.system.shared.event.service;
+
+import org.eclipse.che.api.system.shared.event.EventType;
+import org.eclipse.che.commons.annotation.Nullable;
+
+import java.util.Objects;
+
+/**
+ * See {@link EventType#SERVICE_ITEM_STOPPED} description.
+ *
+ * @author Yevhenii Voevodin
+ */
+public class SystemServiceItemStoppedEvent extends SystemServiceEvent {
+
+    private final String item;
+
+    private Integer total;
+    private Integer current;
+
+    public SystemServiceItemStoppedEvent(String serviceName, String item) {
+        super(serviceName);
+        this.item = Objects.requireNonNull(item, "Item required");
+    }
+
+    public SystemServiceItemStoppedEvent(String serviceName,
+                                         String item,
+                                         @Nullable Integer current,
+                                         @Nullable Integer total) {
+        this(serviceName, item);
+        this.current = current;
+        this.total = total;
+    }
+
+    @Override
+    public EventType getType() {
+        return EventType.SERVICE_ITEM_STOPPED;
+    }
+
+    public String getItem() {
+        return item;
+    }
+
+    @Nullable
+    public Integer getTotal() {
+        return total;
+    }
+
+    @Nullable
+    public Integer getCurrent() {
+        return current;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof SystemServiceItemStoppedEvent)) {
+            return false;
+        }
+        final SystemServiceItemStoppedEvent that = (SystemServiceItemStoppedEvent)obj;
+        return super.equals(that)
+               && item.equals(that.item)
+               && Objects.equals(total, that.total)
+               && Objects.equals(current, that.current);
+    }
+
+    @Override
+    public int hashCode() {
+        int hash = 7;
+        hash = 31 * hash + super.hashCode();
+        hash = 31 * hash + item.hashCode();
+        hash = 31 * hash + Objects.hashCode(total);
+        hash = 31 * hash + Objects.hashCode(current);
+        return hash;
+    }
+
+    @Override
+    public String toString() {
+        return "SystemServiceItemStoppedEvent{" +
+               "item='" + item + '\'' +
+               ", total=" + total +
+               ", current=" + current +
+               ", eventType='" + getType() + '\'' +
+               ", service='" + getServiceName() +
+               "\'}";
+    }
+}

wsmaster/che-core-api-system-shared/src/main/java/org/eclipse/che/api/system/shared/event/service/SystemServiceStoppedEvent.java

@@ -0,0 +1,30 @@
+/*******************************************************************************
+ * Copyright (c) 2012-2017 Codenvy, S.A.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *   Codenvy, S.A. - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.che.api.system.shared.event.service;
+
+import org.eclipse.che.api.system.shared.event.EventType;
+
+/**
+ * See {@link EventType#SERVICE_STOPPED} description.
+ *
+ * @author Yevhenii Voevodin
+ */
+public class SystemServiceStoppedEvent extends SystemServiceEvent {
+
+    public SystemServiceStoppedEvent(String serviceName) {
+        super(serviceName);
+    }
+
+    @Override
+    public EventType getType() {
+        return EventType.SERVICE_STOPPED;
+    }
+}

wsmaster/che-core-api-system/pom.xml

@@ -58,6 +58,10 @@
             <groupId>org.eclipse.che.core</groupId>
             <artifactId>che-core-api-dto</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.eclipse.che.core</groupId>
+            <artifactId>che-core-api-model</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.eclipse.che.core</groupId>
             <artifactId>che-core-api-system-shared</artifactId>
@@ -68,11 +72,15 @@
         </dependency>
         <dependency>
             <groupId>org.eclipse.che.core</groupId>
-            <artifactId>che-core-commons-lang</artifactId>
+            <artifactId>che-core-api-workspace-shared</artifactId>
         </dependency>
         <dependency>
-            <groupId>org.everrest</groupId>
-            <artifactId>everrest-websockets</artifactId>
+            <groupId>org.eclipse.che.core</groupId>
+            <artifactId>che-core-commons-annotations</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.eclipse.che.core</groupId>
+            <artifactId>che-core-commons-lang</artifactId>
         </dependency>
         <dependency>
             <groupId>org.slf4j</groupId>